1. Field of the Invention
The invention relates to apparatus and methods for determining the load size of a cooking system, such as a deep fat fryer. In particular, the invention relates to apparatus and methods for automatically determining the load size of a deep fat fryer and automatically correcting cooking parameters, such as cooking time, cooking temperature, and the like.
2. Description of the Related Art
Large capacity commercial and industrial cooking equipment, such as deep fat fryers are used to cook food products in a heated or a heated and pressurized environment. Such devices are known in the art, as described in U.S. Pat. Nos. 4,930,408, 5,402,712, and U.S. Design Pat. No. 336,007, each of which is incorporated herein by reference. Typically, such devices include a cooking vessel, which may be filled with a cooking substance, e.g., oil or shortening, and heating devices surrounding or immersed in the vessel, or both, for heating the cooking substance. Products to be cooked are placed in the vessel, either directly or in a cooking basket and are heated for a desired length of time. The cooking baskets may be either manually or automatically lifted from the cooking substance when the desired cooking time is finished.
Nevertheless, a problem exists with such cooking devices described above. The required cooking time depends on many process parameters, including food product type, cooking substance temperature, initial product temperature, product moisture content, cooking pressure, load size, and the like. Parameters such as time and temperature may be regulated by an embedded process controller in these devices. Load size, may be merely estimated and is generally selected by an operator. This manual selection often is subject to errors of judgment, or due to haste or inexperience.
It may also be difficult to determine when cooking devices, such as those described above, are not functioning properly. An effective way to determine whether the cooking device is functioning properly involves determining the yield of the cooking product, which is a comparison of the pre-cooking weight of the food product, and the post-cooking weight of the food product. If a food product has a low yield (i.e., its post-cooking weight is significantly less than its pre-cooking weight), the food product may be over cooked, which may be a result of the food product being cooked for too long, the temperature of the cooking substance being set too high, problems with the heating elements, or a combination of these or other factors. If a food product has a high yield (i.e., its post-cooking weight is significantly higher than its pre-cooking weight), the food product may be undercooked, which may be a result of the food product not being cooked long enough, the temperature of the cooking substance being too low, problems with the heating elements, or a combination of these or other factors. Without determining the pre- and post-cooking weights of the food product, it is difficult to determine an accurate yield for a cooking device.